[The anti-leukotrienes: their use in asthma]

Inflammation in asthma plays a predominant role in the genesis of bronchial obstruction and hyperreactivity. Treatment of bronchial inflammation since the early stages of asthma has become an essential element of therapeutic strategy and rests chiefly on inhaled glucocorticoids. However, inhaled glucocorticoids pose some problems in terms of inhalation technique, compliance, local tolerance and, to a lesser extent and at high doses, of systemic tolerance. Antileukotrienes represent a new class of potential anti-asthma drugs. They act either by inhibition of 5-lipoxygenase, a key enzyme in the leukotriene (LT) synthesis pathway, or by blocking LT receptors. The LT antagonists developed in asthma are mainly specific for a receptor subtype, the CysLT1 receptor, involved in the bronchoconstrictor and inflammatory effects of sulfidopeptide leukotrienes (LTC4, D4 and E4). Two antagonists of CysLT1 receptors have been recently launched on the market: ONO-1078, pranlukast, Onon and ICI-204,219, zafirlukast, Accolate. The CysLT1 antagonists cause bronchodilatation with a beta 2-agonist additive effect, confer effective protection in bronchial provocation studies and particularly, they improve clinical scores, pulmonary function and beta 2-agonist rescue inhaler use. Additional studies, especially comparative with respect to reference treatments, mainly inhaled glucocorticoids, will be required to define their place in the global strategy for asthma management.